What is a potential outcome of exceeding the lactate threshold during exercise?

Exceeding the lactate threshold during exercise typically leads to an accumulation of lactic acid in the muscles. This accumulation results in muscle fatigue and a heightened perception of effort, which can decrease overall performance. The lactate threshold represents the point at which lactate begins to accumulate in the bloodstream faster than it can be removed. When this happens, the body is no longer primarily relying on aerobic metabolism, which is more sustainable for longer durations and lower intensities.

As the intensity of exercise increases and crosses this threshold, the reliance shifts towards anaerobic metabolism, leading to quicker energy expenditure but also resulting in fatigue due to the buildup of lactic acid. Consequently, heart rate and breathing rate rise as the body attempts to cope with the changing energy demands, and eventually, performance can decline due to fatigue.

In contrast, outcomes such as increased endurance or improved fat oxidation are typically associated with training adaptations that maintain exercise below the lactate threshold. Enhanced demand for carbohydrates may occur, but it is more a shift in energy substrate usage rather than a direct consequence of exceeding this threshold. Thus, fatigue and decreased performance is the most evident effect that results from surpassing the lactate threshold.